Blade for propellers, ventilating fans, and the like



March 6, 1928.

` A.- cERFvoL BLADE FOR PROPELLERS, VENTILATING FANS, AND THE LIKE Filed July 23. 1926 2 Sheets-Sheet 1 Mmh6,192s. 1,661,921

A. cE'RFvoL BLADE FOR PROPELLERS, VENTILATING FANS, AND THE JIKE Filed July 2:5. 1926- 2 Sheets-Smet 2 i' Egg -llf "n n- 1* y Patented Mar. 6, 1928.

UNITED STATES y f 1,661,921 PATENT 1 OFFICE.

ALBERT CERFVOL, OF BARKING, ENGLAND, ASSIGNOR OF ONE-FIFTH TO OHN ALEX- .ANDERFISHEIEL ONE-FIFTH T0 FREDERICK WILLAM SHEARS, ONE-FIFTH' 10 EDWARD LUMSDEN, AND

ENGLAND.

ONE-FIFTH TO CHARLES RAYMOND, ALL OF LONDON,

BLADE Fon rRorELLERs, VvnivtrrLArINa rens, Ann4 Tris LIKE.

Application led Juiy 23,1926, serial Nb. 124,497, and in. Great isrli'ainruly 7, 1926.

The object of this invention is to construct a blade for air propellers, Ventilating fans and the like,` whereby perfect fiexibility along the whole of the blade is maintained under all conditions of working, thereby nections and the whole or a greater part of` such rods are covered or enclosed with a iexible, springy or jointed material, lso connected as to allow of a certain movement of each rod individually or collectively and of returning or allowing of each rod returning to its normal position.

The covering may be secured together at each side of each rod so that each rod is in its own pocket or the whole rod may be coveredV and the spaces between each rod filled in which springy or resilient means to allow of the movement and return ofthe rods to their normal position.

It is preferred that the blade and its boss be connected to the driving shaft by spring controlled means to which there is an imaginary or positive hinged line running parallel with the axis of rotation, that is to say if the bosses carrying the blades are connected direct to the driving shaft through springy or fiexible .means or the boss can be hinged to the means on the shaft, in which case the action of the blades is further con` trolled by springs and in both cases each blade is given a slight oscillatory movement about its mean position, in addition to which y the action of the air duringrevolution of covered with flexible fabric, part being broy ken to show link connection with the 'free ends of the rods.l 5 v Figure 2 is a section on theline a Ya of Figure l.` y

Figure 3 is a section ony the line b b of Figure 1. i y" "i l Figure 4 is a section on the -line 0 c of Figure l. Figure 5 is any elevation a. blade,`and showing a springmeans tioned between each rod. f

Figure 6 is a section on the line al d of ofFigure.r y Figure 7 is a 'planof the outer ortop posiof a portionof end'y of a' blade showing amodied means of constructing and connecting-the ends of ythe rods. x i I Y.

Figure 8 is aplan view of a `completey propeller with spring means or connection to the driving shaf.

According to this invention, four tapered springy rods l are employed preferably of springy steel and these arescrew threaded at their thicker ends and screwed into holes in a support ,2, the rods l `being positioned slightly fan shaped andin the preferred application to the driving shaft 3 each support is connected to a bell crank lever 4 pivoted to an arm 5 of a boss 6 secured to the shaft 3, the free armof the bell crank lever 4: being pivotally connected rby springs 7 to another arm 5at of the boss 6 as will be understood from Figure 8.

Each bell `crank lever 4 is'screwed into the support 2 and in the construction shown at yFigure l the end rod l is lscrewed into the bell crank lever 4 and the two arms clamped in the split end of the support 2 bolt 2 and embracing the rod is what might ber termed a iiexible stiii'ener i. e. two strips of india rubber 9, .9, see Figure 3, embracing lthe rods and held thereto byv rivets 10 passed between the rods l or in lieu thereof, helical springs 11 may be positioned between the rods l and the whole coveredby a strip l2- the helical springs and strip kbeing kept in place by rivets 13 (see Figure 6).

The free and smaller ends of the rods 1 are connected together by links 14, these being loosely attached to allow' of a movement of either or all. of the rods l, and from lll just beyond the stitfener 9 the remainder of the blade including the links are covered on both sides by a flexible fabric 15 which in additionto being cemented ltogether and to the rods l, are sewn along the sides of the rods r1 as indicated by the dotted lines 16 so that the rods 1 are positioned in pockets, wherebyvthey can always be kept in their proper position with regard to the covering 15. A

Insteadot the smaller ends ot the rods 1 being shaped and connected together .as at yFigure 1, the two outside rods may be to thev thicker ends of the rods, said rods being arranged in fan shape, means for connectiingr the thinner' ends ot' the rods loosely together, a covering consisting ot flexible material encasing the rods and secured thereto, and a flexible stitfener embracing all of the rods at a point between the ends-ot the corerirner and the support.

2. A blade for Propellers, Ventilating fans, and the like, comprising a .series of outer and intermediate tapered spring rods a base support secured to the thicker ends of the rods, said rods heiner arranged in fan shape, a co\-'erinf f consisting of flexible material encasing; the rods` and secured thereto, the thinner ends of the rods being loosely connected together, and a covering for the rods consisting ot a flexible fabric on both sides and securedtogether hy eenlent and to the rods by rows ol stitches on each side of the rods forming pockets therefor.`

A blade for propellers, \-entilatin; fr fans and the like, comprising two outer and an intermediate tapered springl rod disposed Substantially radially relative to each other, means for securing the lthicker inner ends of said rods to form a support tlierelor` flexible means connectingr the outer ends of said rods together and limiting the traus- Verse movement of the rods but permitting a flexingr of the blade, means for connecting said support to a driving! shaft, a covcriner consisting ot flexible material and encasingr the rods secured thereto, and a flexible stitl'ener engaging thc rods adjacent the support.

In testimony whereof l have hereunto eety my hand.

ALBERT CERFVOL. 

